Case shift mechanism for typewriting machines



L w 1 m H 7 a T N m N. 4 m 7 R 3. s mm m m E m 9/ A 3 m M v m mm ow R H Q-T M 0 W Y L B HILL CASE SHIFT MECHANISM FOR TYPEWRITING MACHINES Twl March 17, 1953 Flled June 9 1951 Mai-ch 17, 1953 B. |-u| 2,631,713

CASE SHIFT MECHANISM FOR TYPEWRITING MACHINES Filed June 9,. 1951 3 Sheets-Sheet 2 INVENTOR LAURENCE B. H I LL ATTO R N EY March 17,1953 L. B. HILL 2,631,713

CASE SHIFT MECHANISM FOR TYPEWRITING MACHINES Filed June 9, 1951 3 Sheets-Sheet 3 1 3'" F m 5 i i 1- L 1,4 (n I i io w INVENTOR LAURENCE a. HlLL ATTORNEY Patented Mar. 17, 1953 CASE SHIFT MECHANISM FOR TYPEWRITING MACHINES Laurence B. Hill, Syracuse, N. Y., assignor to L. C. Smith & Corona Typewriters, Inc., Syracuse, N. Y., a corporation of New York Application June 9, 1951, Serial No. 230,720

Claims.

The invention relates to caseshift mechanism for typewriting machines, and has for its general object the provision of improved means for conditioning a typewriting machine for lower and upper case typing by shiftin the type bar segment.

A further object of the invention is to provide a type bar segment shifting mechanism operable by a typist withminimumfinger pressure and finger-shock and with minimum shock transmissiontoother parts of the machine.

A further object of the invention is to provide a type bar segment shifting mechanism having improved means for positively and automatically latching the segment in its normal position for lowercase typingand for unlatching the segment and shifting it into shifted position for upper case typing.

.A further object of the invention is to provide'an improved case shift mechanism for automatically latching ,asegment on its arrival at lower case typing position and for easily unlatching the segment and shifting it to upper case typing position by light finger pressure on a case shift key, and for, at will, latching and unlatching the segment easily while it is in its upper case typing position and without putting undue strain on any part of the shift mechanism.

A further object of the invention is to provide improved means for shifting a type bar segment downwardly from a normal position to a shifted position by :key pressure and restoring the segment by spring power.

A further object of the invention .is to provide an improved key operated, and spring returned mechanism for cheating latching and unlatching movements of a type bar segment latch.

A further object of the invention is to provide aseg-mentshifting mechanism so constructed and arranged as to leave a maximum of space open for other mechanisms of the typewriter.

To the foregoing and other ends which will appear from the following description of the preferred embodiment of the invention shown in the accompanying drawings, the invention conin the combinations of elements, arrangements of parts and features of construction set forth in the following description and particularly pointed out in the appended claims.

In the drawings:

Fig. 1 is a fragmentary vertica1 sectional View of a known style of typew-riting machine equipped with case shifting mechanism embodying the present invention, this view being taken on the line i-.-i of .2, and all parts being shown in their respective normal positions in which the machine is conditioned for lower case typing;

Fig. 2 is an enlarged detail sectional view on the line 2-2 of Fig. 1;

Fig. 3 is an enlarged detail sectional view'on the line 33 of Fig. 1;

Figs. 4 and 5 are views similar to Fig. 1, but on an enlarged scale and illustrating the mode of operation of the mechanism, as more fully hereinafter explained; and

Fig. 6 is a detail sectional view on an enlarged scale and taken on the line 66 of Fig. 4.

The known features of the machine, only so many of which are shown as is necessary to a clear understanding of the invention, first will be described.

The machine-has a sheet metal main frame comprising left and right hand side plates Ill-l 0, a horizontal cross plate ll having flanged ends secured to the side plates by fastening screws, one of which is shown at i2 (Fig. l) and a downwardly and forwardly inclined cross plate l3 having flanged ends held to the side plates by screws it. The key lever guide comb I5 of the machine has flanged ends held to the side plates by screws l6, and this comb carries the key lever stop device H. The platen I8 of the machine is mounted in a carriage (not shown) to travel across the machine above the upper edge of plate The type bar segment It is clamped to the front faceof a sheet metal carrier plate 20, at the upper portion of said plate, by screws 19a to shift with the carrier or supporting plate 20.

The segment l9 and plate 20 lie in parallel planes parallel to frame plate l3, and plate 29 is located closely adjacent the front face of plate I3. The usual arcuate array of type bars is carried by the segment, the type bars being pivoted in slots in the segment in known manner and normally resting in a cumbent position against a type bar rest to strike upward and rearward to the platen. One of the typebars is shown at 2| (Fig. 1), and the type bar rest is shown in part at 22 (Fig. 1) and is carried in known manner by plate 20 to shift with said plate and the segment.

The plate 25 has a lower portion which is of substantially less width than the segment and depends below the segment, and the wider upper portion of said plate has right and left hand ends which extend beyond the right and left hand ends of the segment and are formed with forwardly and upwardly extending ball race flanges 23 which are opposed to forwardly and upwardly extending ball race flanges 25a formed. on two sheet metal brackets 25. The brackets 25 are held to the front face of frame plate It by screws 24. The two races thus formed at opposite ends of the segment extend lengthwise in a plane parallel to plates I3 and 20, and in each such race is confined one of two antifriction bearing balls 83 to slidably and rockably guide the segment [9 and plate in known manner.

The improvements now will be described.

At opposite sides of its narrow lower portion, and below the segment, the carrier plate 26 is formed with two forwardly and upwardly extending bearing ears or lugs 26 equally spaced a short distance to opposite sides of the longitudinal central vertical plane of the machine. Each ear 26 is provided at its outer face with a bearing boss 21. Each bearing boss is recessed to pivot on the conical end of one of two pivot screws 28 which shiftably support the carrier plate at its lower end, as more fully hereinafter described.

A compact and space saving arrangement of adjustable case shift stops is provided for arresting the segment and its carrier plate in a normal position for lower case typing and a lower shifted position for upper case typing. Midway between ears 26, and midway between the side plates [ll of the main frame, the carrier plate 20 is provided with a rearwardly and downwardly extending stop lug 29 lying fiatwise in a plane normal to the plane of the carrier plate. Stop lug projects through a clearance aperture 30 in the 'main frame plate I 3 and is movable down and up in said aperture. At the upper and lower edges, respectively, of aperture 30, the frame plate i3 is formed with a stop lug 3| and a stop carrying lug 32 which are staggered transversely of the machine and extend downwardly and rearwardly from plate l3 with said lugs disposed flatwise in a plane normal to the plane of said plate 13. An adjustable lower case stop 33 underlies lug 3i and has a pendent threaded stem which is threaded through stop lug 29 on the carrier plate and locked in adjusted relation to said lug by a lock nut 34. A similar upper case stop 35 underlies lug 29 and has its threaded stem threaded through lug 32 on plate l3 and locked in adjusted relation to said lug by a lock nut 35. It will be noted that the lugs 29, 3! and 32 extend only a very short distance back of frame plate l3, and that the case shift stops 33 and 35 are located very close to the rear face of said plate, so that the upper portion of this inclined plate overhangs said lugs and stops.

Plate 13 is formed with two short rearwardly and downwardly extending ears 31 which are spaced slightly farther apart than the cars 25 on plate 20 and are located substantially directly downward from the ends of the type bar segment. Extending between the ears 3? is a short horizontal rock shaft 38 the recessed ends of which are journaled on the conical ends of a pair of horizontal pivot screws 39 which are threaded through ears 3! and are held against unscrewing by lock nuts 46. The ears 31, shaft 38 and the pivot screws 39 also are overhung by the upper portion of plate l3 and are located closely behind said plate in a compact space saving arrangement.

Two supporting and shifting levers 4i and $2 for the segment carrier plate 20 are fixed on rock shaft 38 adjacent opposite ends of the shaft. Each of these levers has an arm extending through frame plate 13 and movable down and up in a different one of two clearance apertures 43 in plate l3. The before-mentioned segment supporting pivot screws 28 are threaded through these lever arms near the forward ends of the arms and extend horizontally and in axial alignment transversely of the machine. The axes of said screws and of the bearing balls 83, in both the normal and shifted positions of the segment, are located in a single plane which is parallel to plate It, the screws 28 being movable equal distances above and below a plane which is normal to said plate and contains the axis of the rock shaft 38. Screws 28 are locked in position by lock nuts 28a.

To restore the segment to its higher position for lower case typing, and to fioatingly or buoyantly hold it there so that it may be forced downward with a minimum of effort, the lever 42 is formed with an upwardly and rearwardly extending arm carrying at its upper end a horizontal stud 42a to which is anchored the forward end of an expansion spring 44 which extends rearward and downward from said stud. The rear end of spring 44 is anchored to the forward end of a spring tension adjusting screw 45 which is threaded through a, thumb nut 45 and extends longitudinally of the spring. Nut 45 has a reduced cylindrical forward end portion rotatively journaled in an upwardly and rearwardly extending arm or lug 4 1 struck up from the frame cross plate H. The normal tension of spring 44 is adjusted so that the spring power slightly more than counterbalances the load supported by rock shaft 38 and levers 4i and 42.

The type bar segment is shiftable under control of either of two shift key levers 48 located adjacent opposite sides of the machine and guided in slots in the comb l5. Each lever 48 is provided at its forward end with a shift key as and has its rear end fixed to a rock shaft 59 which extends horizontally across the machine. This shaft has recessed ends journaled on the conical inner ends of two horizontally pivot screws 5! which are threaded through side plates it and are locked against accidental turningvby lock nuts 52. Studs 53 fixed to the side plates Ill above levers 48 are connected with said levers 43 forward of the rock shaft 50 by key lever returning springs 54 which normally hold said levers rocked upward against the key lever stop device H.

A rock arm 55 is fixed at its forward end on rock shaft 58 and extends rearward under frame plate 53 in a vertical plane slightly to the left of lever 4| on rock shaft 38. A horizontal pivot stud 56 pivotally holds the upper end of a pendent latch 51 to the rear end of a short rearwardly extending arm of lever 4|. Latch 51 has at its upper end a short rearwardly extending arm which is connected with the rear end of rock arm 55 by a longitudinally compressible link device. This link device comprises two sheet metal bars 58 and 59 held face to face for positive limited link shortening and extending relative longitudinal movements. Bar '58 is pivotally held at its upper end to the rearwardly extending arm of latch 51 by a shouldered pivot stud 553, and bar 59 is pivotally held at its lower end to the rear end of rock arm 55 by a shouldered pivot screw 61. A shouldered guide and stop screw 62 extends through a short longitudinal closed slot 53 in the upper part of bar 59 to limit contraction and expansion of the link device. Both bars extend through guide openings in two sheet metal disks or washers 64 and 55 which are held engaged respectively with abutment edges 58a and 59a of the bars by a helthe bars between said disks and normally holds the link device fully extended.

Latch ET is guided adjacent its lower end in a slot 61 in a sheet metal latch keeper 68 which is held to frame plate 13 at the rear of said plate by screws 69. ihe hooked lower end of the latch is normally engaged under keeper 6.8 at the forward end of slot ill to positively latch the type bar segment in its normal higher position for lower case typing, as shown in Fig. 1. Bar 58 of the latch device is formed with a, pendent arm 'lil which is bent to provide a horizontal stop lug ll at its lower end which extends behind latch 5'! to positively limit swinging of the latch in rearward or unlatching direction as shown in Figs. 4 and 5. In the normal segment latching position of the latch (shown in Fig. 1) the latch is rocked forward out of contact with lug H. Spring 6-5 is of such strength that the link will not compress or shorten during rocking of the latch 51 to unlatched position, and also is of such strength relatively to the expansion spring 4:?- that the link will not compress or shorten during shifting of the segment from lower case typing position to upper case typing position. 7

It is desirable that there be associated with at least one of the shift key levers a shift lock key controlled device by which a typist, at will, may releasably latch the segment in upper case typing position. One such device is shown associated with the left hand case shift key lever 48. While this device per se is of well known construction, its functioning is rendered more easy and certain, as hereinafter described, by the improved features heretofore described. The construction of this known device now will be described.

The shift lock key 12 is carried on the forward end of a shift lock key lever 13 which is connected at its rear end with the left hand one of the shift key levers 48 by a horizontal pivot stud 'ki. A spring 15 connects said levers l3 and 43 and normally holds lever 13 rocked upward into a position in which a horizontal stop lug '16 on lever '53 is engaged with the lower edge of lever 48, and a second horizontal stop lug H on lever 3 is spaced slightly above the upper edge of lever 48, as shown in Fig. 1. The shift lock key lever '13 extends through a slot in the key lever guide comb l5 and is formed, forward of said comb, with a horizontal shift key lever latch stop lug 73, A shift key lever latch '19. located forward of the comb i5, is connected with the left hand shift key lever it by a horizontal pivot stud til. A latch spring 8! connects the shift lock key lever 73 and latch 79 and normally holds the latch rocked against stop lug 78 on lever '13 with the nose 19a of the latch above and forward of a sheet metal latch keeper 82 which is fixed to comb $5 at the front of the comb. Normally, the parts of the shift lock device, except the keeper, move bodily with the lever 48, and the latch does not engage its keeper.

When a typist desires to shift the segment to upper case position and latch it there, finger pressure is applied to the shift lock key 72. When this is done, the lever l3 first rocks rela tively to lever 48 until lug ll engages the upper edge of lever 48, after which both levers move together. The initial rocking of lever 73 lowers the latch stop lug l8, and the spring 8! then first rocks the latch 19 rearward against the front edge of keeper 82 and finally, after com- '6 plction'of the case shift, rocks the latch farther rearward to position its nose 1912 under the forward end of the keeper, at which time the latch i e-engages stop lug 18. To release the latch 19. the typist presses down on eitherof the shift keys 49 carried by the levers 48, thereby rocking the levers .48, shaft 50 and arm 55 and compressing the link device 5859-66, whereupon spring 15 rocks lever 13 upward relatively to lever 48 until stop 16 engages lever 48. This movement of lever 13 causes lug 18 to rock the latch 19 out from under the keeper and permits spring 44 to act to return the segment to lower case typing position. Obviously, other known forms of shift lock key device could be used instead of the known device shown, and one such device could be provided for each of the shift key levers 48, if desired.

With the segment latched by latch 51 in its higher normal position for lower case typing, as shown in Fig. 1, a typist may shift the segment downward to its shifted position for upper case typing .by depressing either of the shift keys 49 on shift key levers 48, and may effect return of the segment to normal position by relieving finger pressure on the key. Depression of a shift key 49 rocks the two levers 48, shaft 59 and arm 55 against the resistance of the two springs 54 and thrusts the compressible link device upward. Upward movement of the link device first rocks the latch 51 on its pivot into its unlatched position in which it engages stop H on the link device, and this movement of latch 51 is completed before any shifting force is transmitted to lever 4| and the type bar segment, as shown in Fig. 4, so that the latch is releasable by light pressure on the shift key 49. Continued de" pression of key 49 causes the abutted latch device and link to move bodily upward, thereby transmitting upward thrust to the rear arm of lever 4| and rocking said lever 4|, lever 42 and shaft 38 against the resistance of spring 44 until the segment is arrested in its lowered position for upper case typing by engagement of case shift stops 29 and 35, as shown in Fig. 5. At this time key 49 will be pressed down to the lower position thereof shown in dotted lines in Fig. 5. Up to this time the compression spring 66 holds the link device fully extended. Continued pressure on the key will drive the key still farther downward, as shown in full lines in Fig. 5, and compress the link device as shown in Fig. 5. This final cushioning action of the link relieves shock on a typists finger and prevents injurious strain on the segment shifting mechanism and on the stops 29 and 35 when either shift key is operated with a strong finger pressure. It also permits easy depression of either shift key 49 into the over-depressed position. shown in full lines in Fig.5, to easily free or release the shift lock key device without springing or straining the shift mechanism when the segment has been shifted by the shift lock key 12 and latched in shifted position by latch 19.

When pressure is relieved on a depressed shift key 49, the springs 44 and 54 quickly restore the parts to the position shown in Fig. 4, in which position of the parts the segment is arrested in its normal lower case typing position by engagement of case shift stops SI and 33 and is there yieldingly held by spring 44. In this position of the parts spring 44 is .no longer effective to move the latch 51. the link device 58-59, rock arm 55 and the shift key levers from their respective positions shown in Fig. 4 to their normal'positions shown in Fig. 1, but said parts will be so restored by the continued upward pull of springs 54 on the shift key levers 4B. Latch 51 is thus easily rocked into latching position after thereturn shift of the segment has been completed. It requires only very light pressure on either of the shift keys to release the latch 5'! or shift lock latch 19 or to force the segment down to its shifted position for upper case typing.

I claim:

1. A typewriter having a case shift mechanism comprising, in combination, a case shiftable carrier for a type bar segment, means for arresting the carrier at a normal and a shifted position, a carrier shifting support hinged to the carrier and oscillative about a fixed horizontal axis which extends transversely of the typewriter, spring means connected to the support to shift the carrier to its normal position, a stationary latch .keeper, a latch connected to the support by a horizontal pivot and rockable about said pivot for releasable engagement with the keeper to hold the carrier in normal position, a stop against which the latch is rockable upon its disengagement from the keeper, a case shift key, means connected with said latch by a horizontal pivot and operable by pressure on said key to first rock said latch against said stop and then rock the oscillative support through the medium of the latch and latch pivot to shift the carrier to its shifted position, and a second spring means conneoted to said key operable means to return the key operable means and the key when pressure on the key is relieved and also to cause said key operable means to rock the latch into latching engagement with the keeper after the carrier is restored to normal position by the first mentioned spring means.

2. A typewriter, as claimed in claim 1, wherein said key operable means includes a lever structure which carries the shift key and is rockable about a horizontal axis which extends transversely of the typewriter, and a link connected to said lever structure and said latch by horizontal pivots, and wherein said second spring means is connected to the lever structure.

3. A typewriter, as claimed in claim 2, wherein said link is yieldingly extensible and contracuible within fixed limits longitudinally and resists con traction under pressure on the shift key until the carrier is arrested in its shifted position.

4. A typewriter, as claimed in claim 1, wherein said key operable means includes a reciprocable link which is connected to the latch by a horizontal pivot to rock the latch, and wherein the stop against which the latch i rockable is carried by said link.

5. A typewriter having, in combination, a type bar segment carrier, a case shiftable support for the carrier, means for arresting the carrier in a normal a shifted position, spring means connected to the support to shift th carrier to normal position, a stationary latch keeper, a latch pivotally held to the support for releasable engagement with the keeper to positively hold the carrier in normal position, a stop against which the latch is rockable upon its disengagement from the keeper, shift key controlled means positively connected with said latch and operable to disengage the latch from the keeper and engage it with said stop and thereafter shift said support against the resistance of the first mentioned spring means to shift the carrier to its shifted position, and a second spring means con-i nected to said shift key controlled means to actuate the latter to engage the latch with its keeper upon restoration of the carrier to normal position by the first mentioned spring means and said support.

6. A typewriter, as claimed in claim 5, wherein said stop is carried by said shif key controlled means to shift in unison with the latch while the latch and stop are in engagement.

7. A typewriter having a case shift mechanism comprising a case shiftable support, means for arresting the support in a normal and a shifted position, spring means connected to the support to shift it to normal position, a stationary latch keeper, a pendent latch hook connected to the support by a horizontal pivot for releasable hooking thereof under the keeper to hold the support in normal position and having an arm extending laterally of said pivot, a horizontal rock shaft, a case shift key carrying arm fixed to and extending forward from said rock shaft, a rock arm fixed to and extending rearward from said rock shaft, an upstanding link connected by horizontal pivots at its upper end to said latch hook arm and at its lower end to said rock arm, and a second spring means for rocking said shaft and the arms fixed thereto into a normal position in moving to which the link rocks the latch hook into hooked engagement with the keeper, said latch hook being first rockable out of engagement with the keeper and into engagement with the link by downward rocking of the shift key carrying arm and thereafter movable in unison with the link to shift the support to its shifted position by further downward movement of the key carrying arm.

8. A typewriter, as claimed in claim '7, wherein said link is yieldingly compressible longitudinally under down thrust on th case shift key greater than that required to shift the support against the force of the first mentioned spring means.

9. A typewriter, as claimed in claim 8, having a second stationary keeper adjacent the shift key carrying arm, and a shift lock key and a latch controlled thereby mounted on said shift key carrying arm for rocking said arm to shift the support to shifted position and engaging said latch with the second keeper to lock the support in shifted position, said shift lock key controlled latch being releasable from its keeper by rocking the shift key carrying arm downward and compressing the link while the support is in shifted position.

10. A typewriter having, in combination, a downwardly and forwardly inclined frame plate extending transversely of the typewriter, an oscillative case shift support journaled on said plate immediately behind the lower portion of said plate and extending through apertures in the plate, stop means immediately behind the lower portion of the plate for arresting said support in a normal and a shifted position, spring means located behind the plate and connected to said support to shift it to its normal position, said support being oscillative about a horizontal axis extending transversely of the typewriter, a latch keeper immediately behind and fixed to the lower portion of said plate, a pendent latch book behind the plate and connected by a horizontal pivot to said support behind the axis of the support and rockable forward to engage under said keeper and positively hold the support in normal position, said latch hook having an arm extending rearward from its pivot, a horizontal rock shaft extending transversely of the machine forward of the plate, a pair of forwardly extending case shift key carrying arms fixed to said rock shaft adjacent opposite sides of the typewriter, a rock arm fixed to said shaft and extending rearward under the plate, an upstanding link behind said plate and connected by horizontal pivots at its lower end to said rock arm and at its upper end to the rearwardly extending arm of the latch hook, springs means for rocking said key carrying arms upward to engage the latch hook with the keeper, and a stop carried by the link behind the latch hook to arrest rearward rocking 10 of the latch hook after it is disengaged from the keeper.

LAURENCE B. HILL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 10 Number Name Date 1,426,242 Baeseler Aug. 15, 1922 1,433,112 Barr et a1 Oct. 24, 1922 

